Conventional Ophthalmic Ultrasound Bio-Microscope (UBM) apparatus includes a UBM scanner having a hand manipulated single UBM probe with a single UBM transducer for in vivo eye examinations for a wide range of clinical applications. The UBM probe can be optionally mounted on an articulated arm for supporting its weight. UBM probes typically operate either at 35 MHz frequency or 50 MHz frequency for anterior segment imaging purposes. Such UBM probes are capable of acquiring UBM scan resolutions of about 25 μm axial resolution and about 100 μm lateral resolution. Higher frequency UBM probes at over 80 MHz are also available for imaging superficial pathologies or anatomical structures such as, Schlemm's canal, and the like. Some UBM probes are provided with interchangeable UBM transducers.
One particular clinical application of UBM scanners is facilitating positioning of one type of intraocular lenses intended for posterior chamber implantation, namely, so-called Intraocular Contact Lenses (ICLs). IntraOcular Lenses (IOLs) designed for posterior chamber implantation are commonly classified into the following three main categories each presenting its own challenges regarding selection, design and positioning:
First, so-called phakic IOL considered to be Intraocular Contact Lenses (ICLs) deployed between an iris and a crystalline lens by ciliary sulcus support. The distance between an ICL's posterior surface and a crystalline lens's anterior capsule is required to greater than 250 μm and smaller than 750 μm. Positioning an ICL too close to a crystalline lens less than 250 μm can result in friction leading to the formation of a cataract at its points of contact. Against that, positioning an ICL too forward might urge an ICL into an anterior chamber possibly leading to pupillary block glaucoma and/or damage to a corneal endothelium. The correct positioning of ICLs is even more difficult and critical when they are also being used for correction of astigmatism. At present, the estimated percentage of positioning related complications is about 15% including cataract formation and optical errors related to inadequate positioning.
Second, pseudophakic IOLs for implantation inside a vacated capsular bag (so-called in the bag IOLs) as a sequential step after removal of a cataractous crystalline lens. For pseudophakic IOLs, the challenges include the ability to calculate a required optical power of an implanted IOL to provide optimal vision correction and predict an accurate IOL position in a capsular bag and hence the optimal location of an IOL along an implanted eye's visual axis. This optimal location is a result of a force balance between an IOL and a capsular bag with all its zonuli attached. The key for accurate IOL power calculation is the ability to analyze the equilibrium point between a capsular bag and an IOL to be implanted. At the present time, the optical power of IOLs currently implanted during cataract surgery is calculated using an estimated location of an implanted IOL inside a capsular bag. This estimated location is the source of optical deviation of the surgical outcome from optimal optical results.
And third, accommodating IOLs which are pseudophakic optomechanical devices designed to restore accommodation by being operated by a minute movement range provided by a capsular bag-zonuli-ciliary muscles complex. Accommodating IOLs have similar optical challenges as pseudophakic IOLs and in addition also require accurate mechanical adjustments with the ocular tissues which operate them.
There is a need to provide ophthalmic apparatus for use in a wide range of in vivo clinical applications. Such clinical applications include inter alia examination of anterior segment structures including eye wall structures, for example, Schlemm's canal, and the like. Also, the selection, design and positioning of the aforesaid three IOLs categories in human eyes.